Officials cast wide net in search for answers

Military and federal officials investigating Thursday's mass shooting at this sprawling Army post spent the weekend poring over evidence they seized from the apartment of the alleged shooter, Army Maj. Nidal M. Hasan, including his computer and multiple e-mail accounts he may have controlled, according to a law enforcement source.Investigators have interviewed 170 witnesses and plan to question more as they try to piece together what might have motivated Hasan, an Army psychiatrist, to gun down 12 soldiers and one civilian, Army officials said.

Hasan was sitting with hundreds of other soldiers, filling out paperwork in a cubicle, when he suddenly stood up and opened fire, said Army officials. More than a dozen of those who were killed and wounded Thursday were soldiers who were close to deploying with him and would have served alongside him in Afghanistan as mental health professionals.

Two of those killed were captains; one was a psychologist who had come to America barely able to read English. Of the 38 who were injured Thursday, fewer than half remain hospitalized. Two victims remain in the surgical critical unit.

All evidence suggests that Hasan acted alone, said a spokesman for the Army's Criminal Investigative Division and investigators have released no information that would link the case to a terrorist group. Texas Gov. Rick Perry (R) told reporters at a news conference Saturday that the shooting was an "isolated" incident, and President Obama, after being briefed by FBI Director Robert S. Mueller III, cautioned that the public should not rush to judgment about the case.